Glass transition, crystallinity, resin stiffness, and branch distribution in metallocene and Ziegler-Natta ethylene 1-olefins

The physical properties of commercially obtained metallocene and Ziegler-Natta (ZN) polyethylenes (PEs) were correlated to their backbone structure (i.e., the composition, ethylene sequence distribution, and short-chain branch length) using dynamic mechanical analysis and thermal fractionation. The uniformity or heterogeneity of the 1-olefin branch distribution on the ethylene backbone profoundly controls the mean crystalline ethylene segment lengths, the degree of crystallinity, the beta transition temperature and intensity, the plateau modulus, and the presence or absence of the alpha transition.